PH is the measure of the level of acidity of a solution. Scale of PH has a range from 0 to 14. A PH of 0 to 6 means that the solution being tested is an acid. PH of 0, 1, 2 means that solution is a strong acid while other numbers of acidic range shows the weak acid solution. PH of 7 means that solution is neutral. PH of 8 to 14 is the indication of a base. 12, 13 and 14 represents the strong base.

In the second part of your question you have asked the reason why a liquid with a PH of 5 is ten times as acidic as a liquid with a PH of 6. For the answer of this part let us first know the mathematical form of the PH. Mathematically PH is PH = -log [H+]H+ represents the hydrogen ion concentration in the above equation. Using the equation described above, you can calculate the level of acidity yourself. From this equation you can see that order of acidity changes as the power of ten. This is the reason of this much difference in acidic level with just a PH difference of 1.

In the second part of your question you have asked the reason why a liquid with a PH of 5 is ten times as acidic as a liquid with a PH of 6. For the answer of this part let us first know the mathematical form of the PH. Mathematically PH is PH = -log [H+]H+ represents the hydrogen ion concentration in the above equation. Using the equation described above, you can calculate the level of acidity yourself. From this equation you can see that order of acidity changes as the power of ten. This is the reason of this much difference in acidic level with just a PH difference of 1.